Medical Stent

ABSTRACT

In an embodiment, a stent is provided for use in blood vessels with blockage near or in a bifurcation. The stent includes a side aperture. The stent is inserted into one of the daughter branches of the bifurcation and positioned with the use of markers. The stent is then expanded so as to support the wall of the blood vessel while allowing the blood to continue to flow to both daughter branches.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/614,228, filed Nov. 6, 2009, which is a continuation-in-partapplication of U.S. patent application Ser. No. 11/221,242, filed Sep.7, 2005, now U.S. Pat. No. 7,632,304, the disclosure of which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the field of medical devices, morespecifically to the field of implantable stents.

DESCRIPTION OF RELATED ART

As is known, the human heart circulates blood throughout the body.Depending on the individual, the heart beats between 80,000 and 140,000times per day. During normal function of the heart, the left and rightatria and the left and right ventricles contract, causing blood to flow.The blood flows from the heart, passes through a set of blood vesselsknown as arteries that feed the organs and tissue in the body and thenreturns to the heart through a set of blood vessels known as veins. Thiscirculation provides nutrients and oxygen to the body so that it cancontinue to function.

As the heart is basically a continuously functioning muscle, it alsoneeds a steady supply of nutrients in order to function. For example, acoronary artery supplies blood (and the associated oxygen and nutrients)to the cardiac muscle. In order for the heart to continue to function,it is crucial that this artery continue to function properly.

Unfortunately, the coronary artery can become partially or completelyblocked. One cause is left main coronary artery disease (“LMCD”). LMCDmay be caused, for example, by the accumulation of fatty tissue on thewall of the left main artery. LMCD is generally defined as a greaterthan 50% reduction in the left main, which results in insufficient bloodflow to the heart tissue and eventually causes damage to the hearttissue.

While partial blockage can result in permanent damage to the heartmuscle, sudden complete blockage of the left main will result in thedeath of the individual. Therefore, maintaining blood flow through theleft main is crucial to an individual's ability to exist. Anysymptomatic blockage must be immediately treated.

Two methods of treatment of a partially or completely blocked left mainare 1) percutaneous transluminal coronary angioplasty (“PTCA”), alsoreferred to as percutaneous coronary intervention (“PCI”), and commonlyreferred to as balloon angioplasty or angioplasty, and 2) coronaryartery bypass graft (“CABG”), commonly referred to as bypass surgery.Due to a number of factors, the most common procedure to treat LMCD hasbeen bypass surgery.

In essence, bypass surgery uses section of veins or arteries sectionsfrom other parts of the body to connect the aorta to a point downstreamof the blockage. This allows blood to flow around the blockage pointthrough a separate passageway. Depending on the severity and location ofthe blockage, as many as four to five grafts are necessary.

One downside to bypass surgery is that it takes a substantial time toperform. For a patient with a totally occlusion or a severely blockedleft main, the time it takes to perform bypass surgery may be too long.Therefore, in emergencies, balloon angioplasty has been performed onpatients suffering from sudden LMCD.

Another problem is that bypass surgery is only effective for about 8-10years, at which point a patient generally requires additional treatmentthat is generally less effective. Given the potential long-term healthproblems, it is desirable to delay bypass surgery if possible.

Furthermore, certain patients' medical conditions are incompatible withthe rigors of bypass surgery. For example, some patients have severeco-morbid conditions precluding open-heart surgery, such as malignancywith limited life-expectancy, no longer are a candidate for bypasssurgery. Thus, while bypass surgery is a useful medical procedure thathas saved many lives, it is best saved for situations where less complexprocedures cannot be used effectively.

In addition, some interventional cardiac catheterization labs are notbacked up by surgical programs. This is problematic in situations wherethe LMCD must be treated immediately (e.g. iatrogenic dissection of theleft main).

Compared to bypass surgery, angioplasty can be done relatively quicklyand is generally less traumatic to the patient. Basically, duringangioplasty a wire is inserted into the artery. A flexible catheter isthen guided along the wire. A balloon attached to the catheter ispositioned in the left main at the point of blockage and the balloon isinflated to open the artery. To keep the artery open, a stent may beplaced in the left main. One common method of delivering the stent is towrap it around the balloon. Thus, the inflation of the balloon causesthe stent to expand into position. The stent acts as a scaffolding tosupport the wall of the artery and, when coated with anti-restenoticagents, can be an alternative means of treating certain types of LMCD.

While the expansion of blocked portions of arteries with angioplasty canbe effective, certain areas of the left main have proven difficult totreat with balloon angioplasty. Sometimes the blockage occurs at a pointof junction between the left main and the left anterior descendingartery and the left circumflex artery. In such a situation, expansionand insertion of a stent into one of the secondary branches has thetendency to jeopardize the other branch.

Attempts have been made to provide a customized stent that can be usedin a junction to support the main branch and the two secondary branchesbut such an approach has limitations. For one thing, the secondarybranches and angles between the different branches are varied fromperson to person as well as from junction to junction, making itdifficult to design a single stent that can work with all the potentialvariations. Furthermore, such a design is difficult to install, thusmaking it less attractive to locations such as the junction in the leftmain. Another major limitation is that much higher operator skill isrequired to position such a stent quickly, thus making it more likelythat such a stent will be improperly installed. Therefore, often theonly choice is to attempt bypass surgery. However, in the face ofcomplete blockage it is possible that a patient will not survive theprocedure. Clearly, something more is needed to address such alife-threatening emergency. In addition, it would be beneficial toprovide a stent that could be used in and near the left main junctionduring more routine medical situations as an alternative to bypasssurgery. Further, other medical fields would greatly benefit fromimproved stents and methods for implanting stents.

Furthermore, in certain medical procedures, two or more stents are oftenimplanted in close proximity to each other. In certain instances, it ishighly desirable to join two stents in a parallel-like fashion. Becauseof individual variation and other factors, it is often too difficult toprecisely join two or more stents. Problems associated with this aredescribed in more detail below in relation to FIG. 29. Reducing oreliminating problems often associated with joining two or more stentswould be beneficial to several medical fields.

BRIEF SUMMARY OF THE INVENTION

Aspects of the invention relate to medical stents and methods forimplanting medical stents. One aspect relates to novel stents thatinclude at least one extension extending in a substantially continuousform from the stent. In one embodiment, the extension extends from aportion of an aperture on a side of the stent. The extension may bepresent over the perimeter of the aperture, for example, forming ahood-like protrusion that arches over the perimeter. In one embodiment,the extension extends at least about 25-30% around the perimeter. Inother embodiment, the extension extends less than about 50% of theperimeter. In one embodiment, the extension extends about 100% aroundthe perimeter, however, has a shorter length on one side extending fromthe aperture than another side extending from the aperture.

The extension may be configured to be in a collapsed state and, uponexpansion of the stent, may be configured to flex outward from the mainbody of the stent. In certain embodiments, one or more markers may bepositioned on a cylindrical body of the stent and/or the extension. Inone embodiment, a first marker may be positioned in-line with anddirectly extending from the location where the distance of the aperturealong the latitudinal direction is the greatest. The first marker may beconfigured to provide a rotation orientation of the stent in adimensional image. In another embodiment, a marker may be positioned onthe extension. In one embodiment, the marker arches in a latitudinaldirection over the perimeter of the aperture in a direction that issubstantially perpendicular to a longitudinal axis of the stent so as toprovide a rotation orientation of the extension in a dimensional image.One such marker may create an arch across the furthest point away fromthe aperture. The marker may be directly aligned with a centerline ofthe side aperture. One marker may be positioned parallel with thelongitudinal axis of the cylinder wall of the stent. In embodiments withtwo or more markers, a first marker and a second marker may beconfigured so as to appear substantially perpendicular to each other ina two dimensional image and the second marker is positioned adjacent theside aperture and extends a distance at least equal to a greatestlongitudinal distance of the side aperture.

Certain aspects of the invention relate to methods relating to medicalstents. In one embodiment, an exemplary method is directed towardssupporting a wall in a junction, such as of a blood vessel. A methodaccording to certain embodiments may be implemented in a junction havinga main branch that extends to a first branch and a second branch,although additional branches are within the scope of furtherembodiments. In one embodiment, a stent with a side aperture may bepositioned in the junction. In one method, a stent is implanted in whichthe extension arches in a latitudinal direction over the perimeter ofthe aperture in a direction that is substantially perpendicular to alongitudinal axis. Yet, in further embodiments, the extension may archalong any direction.

Certain methods may utilize a stent with one or more markers. In oneembodiment, the stent may have a marker aligned with the side apertureat a location where a distance of the aperture along the latitudinaldirection is the greatest. The marker may extend along a circumferenceof the stent a distance substantially perpendicular to a longitudinalaxis of the stent as to, in accordance with certain embodiments, providea rotational orientation of the stent in a dimensional image. In oneembodiment, the method is configured to allow the implantation of astent with a marker that creates an arch across the furthest point awayfrom the aperture. In another embodiment, two or more markers mayconfigured so as to appear substantially perpendicular to each other ina two dimensional image. The marker may be positioned adjacent to theside aperture and extends a distance at least equal to a greatestlongitudinal distance of the side aperture.

Certain methods may expand the stent so as to support the wall of themain branch and the first branch, whereby the side aperture allows themain branch to continue to feed both the first and the second branch.The stent may include an extension, which in accordance with one or moreembodiments, be expanded to extend in a substantially continuous formfrom a portion of the side aperture's perimeter. In one embodiment, theextension may flex outward from the cylinder wall form a protrusion thatarches in a latitudinal direction over the perimeter and extends intothe second branch. The expansion of the stent may be a result of theexpansion of the stent. In one embodiment, the expansion of theextension occurs after the expansion of the stent.

Further embodiments may include the insertion of a guide wire. In suchembodiments, a balloon may be positioned over the guide wire and into abifurcation of the branch with the stent positioned on the outside ofthe balloon. In one embodiment, a portion of a stent may be insertedinto a first branch and a marker may be aligning the marker with thesecond branch. In one embodiment, the stent with a side aperture isinserted into a junction of a left main coronary artery that includes amain branch and two secondary branches so that the side aperture alignswith one of the secondary branches while the stent extends into theother secondary branch. In one embodiment, a stent may be expanded so asto support a wall of the left main coronary artery while allowing bloodto flow through the side aperture into one of the secondary branches. Incertain embodiment, the stent (including the extension) may be coatedwith a pharmaceutical agent.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitedin the accompanying figures in which like reference numerals indicatesimilar elements and in which:

FIG. 1 illustrates an embodiment of a human heart.

FIG. 2 illustrates an enlarged view of the human heart in FIG. 1,illustrating the left main coronary artery.

FIG. 3 illustrates a further enlarged view of the left main coronaryartery of the human heart depicted in FIG. 2.

FIG. 4 illustrates an embodiment of blockage in an artery of a humanheart in accordance with an aspect of the present invention.

FIG. 5 illustrates an alternative embodiment of blockage in an artery ofa human heart in accordance with an aspect of the present invention.

FIG. 6a illustrates an alternative embodiment of blockage in an arteryof a human heart in accordance with an aspect of the present invention.

FIG. 6b illustrates an alternative embodiment of blockage in an arteryof a human heart in accordance with an aspect of the present invention.

FIG. 7 illustrates an embodiment of a guide wire being inserted intocoronary in accordance with an aspect of the present invention.

FIG. 8 illustrates an embodiment of an angioplasty balloon beinginserted into coronary in accordance with an aspect of the presentinvention.

FIG. 9 illustrates a top view an embodiment of a stent in accordancewith an aspect of the present invention.

FIG. 10 illustrates a side view of the stent in FIG. 9 in accordancewith an aspect of the present invention.

FIG. 11 illustrates a side aperture of a stent in accordance with anaspect of the present invention.

FIG. 12 illustrates a sectional view of an embodiment of a stentimplanted in accordance with an aspect of the present invention.

FIG. 13 illustrates a sectional view of an embodiment of a guide wirebeing inserted in accordance with an aspect of the present invention.

FIG. 14 illustrates a sectional view of an embodiment of a stent beingimplanted in accordance with an aspect of the present invention.

FIG. 15 illustrates a sectional view of an embodiment of a stent beingimplanted in accordance with an aspect of the present invention.

FIG. 16 illustrates an elevated view of an embodiment of a supportstructure created by two stents in accordance with an aspect of thepresent invention.

FIG. 17 illustrates an elevated view of an embodiment of a supportstructure created by two stents in accordance with an aspect of thepresent invention.

FIG. 18 illustrates an elevated view of an embodiment of a stent inaccordance with an aspect of the present invention.

FIG. 19 illustrates an elevated view of an embodiment of two markers inaccordance with an aspect of the present invention.

FIG. 20 illustrates an alternative elevated view of an embodiment of thetwo markers in FIG. 19 in accordance with an aspect of the presentinvention.

FIG. 21 illustrates an alternative elevated view of an embodiment of thetwo markers in FIG. 19 in accordance with an aspect of the presentinvention.

FIG. 22 illustrates a top view of an alternative embodiment of a stentin accordance with an aspect of the present invention.

FIG. 23 illustrates a side view of the stent depicted in FIG. 22 inaccordance with an aspect of the present invention.

FIG. 24 depicts a stent in a compressed state in accordance with anaspect of the present invention.

FIG. 25 shows an exemplary stent with an extension in accordance withone embodiment of the invention. Specifically, FIG. 25A shows aperspective side view of the exemplary stent and FIG. 25B shows a topview of the exemplary stent.

FIG. 26 shows an exemplary stent with an extension in accordance withone embodiment of the invention. Specifically, FIG. 26A shows aperspective side view of the exemplary stent and FIG. 26B shows a topview of the exemplary stent.

FIG. 27 shows a perspective side view of an exemplary stent with anextension in accordance with one embodiment of the invention.

FIG. 28 shows a perspective view of an exemplary stent with an extensionin accordance with one embodiment of the invention.

FIG. 29 shows a support structure created by two stents. Specifically,FIG. 29A shows a perspective view of a first support structure and FIG.29B shows a perspective view of a second support structure.

FIG. 30 shows an exemplary stent with an extension in accordance withone embodiment of the invention. Specifically, FIG. 30A shows aperspective side view of the exemplary stent and FIG. 30B shows a topview of the exemplary stent.

FIG. 31 shows an exemplary stent with an extension in accordance withone embodiment of the invention. Specifically, FIG. 31A shows aperspective side view of the exemplary stent and FIG. 31B shows a topview of the exemplary stent.

DETAILED DESCRIPTION OF THE INVENTION

The description below will discuss various medical conditions and how astent may be used to aid in the treatment these medical conditions. Itis noted that the methods and apparatus disclosed are not limited to thetreatment of the medical conditions disclosed but may be used to treatother medical conditions where appropriate.

Looking first at FIG. 1, an embodiment of a heart 10 is depicted. Theheart 10 is fed by a right coronary artery 20 that branches out andprovides blood to a portion of the heart. A left coronary artery 40 isalso shown and also branches out and provides blood to a portion of theheart. As can be appreciated, a blockage at the beginning or proximalend 41 of the left coronary artery 40 would affect the flow of blood toall points downstream while a blockage at the distal end 49 of the leftcoronary artery 40 might have little or no discernable effect on theviability of the heart 10.

Turning to FIG. 2, the left coronary artery 40 is shown in an enlargedview that includes the left main artery or main branch 42 that feeds afirst branch 44 (which as depicted is the left anterior descendingartery) and a second branch 46 (which as depicted is the left circumflexartery).

As depicted in FIG. 3, the first branch 44 shows a further enlarged viewof the left coronary artery 40. The main branch 42 forms a junction 50where it bifurcates into the first branch 44 and the second branch 46.As can be further appreciated, the main branch 42 includes a wall 43. Inorder for blood to flow through the left coronary artery 40, the wall 43forms a tube-like shape that preferably is free from blockage.

Unfortunately, as shown in FIG. 4, a blockage 62 may be formed by, forexample, deposits of fatty tissue on the wall 43 in the junction 50. InFIG. 4, the blockage 62 partially occludes the flow of blood into thesecond branch 46. FIG. 5 depicts a similar situation except that theblockage 64 partially occludes the first branch 44.

FIG. 6a illustrates a blockage 66 in the junction 50 that occludes bloodflow to both the branch 44 and the branch 46. FIG. 6b illustrates ablockage 68 that is not within the junction 50 but affects blood flow tothe first branch 44 and the second branch 46. As can be appreciated byFIGS. 4-6 b, blockage in or near the junction 50 tends to require asolution that allows blood to flow to both branches 44, 46. It is notedthat numerous other configurations of blockage near or in the junction50 are possible. In an embodiment the blockage will occlude the mainbranch; in alternative embodiments the first branch or the second branchor a combination of two or more branches will be occluded by theblockage.

Turning to FIG. 7, an illustration of the left coronary artery 40without any blockage depicted is provided, the blockage being omittedfor the sake of clarity. In an embodiment a guide wire 70 may beinserted into the left coronary artery 40 in a known manner. Asdepicted, the guide wire 70 is inserted into the junction 50 and extendsinto the first branch 44. As can be appreciated, the distance the guidewire 70 extends into the junction 50 may be adjusted depending on thelocation of the blockage.

Turning to FIG. 8, after the guide wire is inserted, the next step is toguide a catheter 80 connected to an angioplasty balloon (“balloon”) 90along the guide wire into the desired position. Once the balloon 90 iscorrectly positioned, the balloon 90 is inflated so as to open up theportion of the left coronary artery 40 that was stenosed by theblockage. To help keep the left main open, the balloon 90 includes astent 100 (not shown in FIG. 8) mounted on the exterior of the balloon90. When the balloon 90 is expanded to open up the passageway, the stent100 is also expanded. Once the passageway is opened, the pressureinflating the balloon 90 is removed and the balloon 90 contracts.However, the stent 100 remains in position so as to provide support forthe wall 43 of the left coronary artery 40.

It should be noted that the balloon 90 may be compliant ornon-compliant, depending on the intended use. Generally speaking,balloons that are non-complaint have a fixed amount of expansion and donot effectively increase in diameter in response to increases ininternal pressure. In contrast, balloons that are compliant doeffectively increase in diameter in response to increases in internalpressure. The balloon 90 may also be semi-compliant and thus providesome minimal amount of expansion in response to greater pressure. Whiledifferent levels of compliance may be suitable for different situations,a non-compliant balloon may be useful to prevent the balloon 90 fromexpanding in the area where the side aperture is provided.

One concern regarding the use of angioplasty is restenosis. Restenosis,or the re-narrowing of the arteries, affects a percentage of patientsreceiving angioplasty. While the use of a stent in combination with theangioplasty has significantly reduced the occurrence, restenosis isstill an issue. To address this potential problem it may be desirable tocoat the stent with a pharmaceutical agent. While differentpharmaceutical agents work differently, in an embodiment, the drugcoating may be configured to provide an anti-restenotic oranti-neointimal proliferation effect. In an embodiment, the coating maybe RAPAMYCIN or SIROLIMUS.

As can be appreciated from FIG. 8, using a standard stent in thejunction 50 would be problematic. For example, in FIG. 8 if a standardstent was used, when the stent was expanded the passageway to the secondbranch 46 would be as least partially blocked.

Looking at FIG. 9, an alternative to the normal stent is depicted asstent 100. The stent 100 has a proximal end 101, a distal end 102 andincludes a side aperture 105, a first marker 112 and a second marker110. The use of the markers will be discussed below. FIG. 10 illustratesa side view of the stent 100. As can be appreciated from FIGS. 9 and 10,the side aperture 105 is circular.

In an embodiment it may be desirable to provide a side aperture that iselongated on one side. FIG. 11 illustrates an embodiment of a sideaperture 105 that includes a center line 106 and is elongated on oneside of the center line 106.

Looking ahead to FIGS. 22 and 23, an alternative embodiment of a stent100 is depicted. The stent 100 includes a proximal end 101 and a distalend 102. A cylinder wall 104 that opens at the proximal end 101 and thedistal end 102 includes a side aperture 105. It should be noted that thecylinder wall 104 of the stent 100 is configured to allow the stent 100to expand. Thus, the cylinder wall 104 may comprise any of the knownwall designs used for expanding stents. As can be appreciated, the sideaperture 105 is shown with a center line 106. It is noted that inpractice the center line 106 would not be visible and is thus beingprovided as a reference for purpose of discussion. As depicted, the sideaperture 105 is elongated on one side of the center line 106, thusmaking it more difficult to define the true center. For purpose ofdiscussion, however, the center line 106 as used herein refers to animaginary reference line on the side aperture 105 that the operatorshould attempt to align with the center of the second branch 46 (FIG.3). As can be appreciated, as the center line 106 is an imaginaryreference line that is not visible to the operator, the markers that maybe provided on the stent 100 can aid the operator in performing thealignment process. Thus, the markers may aid the operator in effectivelyaligning the center line 106 with the side branch 46. It is noted thatin an embodiment the first marker 112 may be aligned with the centerline 106.

It should be noted that as depicted the side aperture 105 provides arelatively smooth edge 109 in the cylinder wall 104. While not required,this allows a second stent to be inserted through the side aperture 105with less likelihood of snagging the stent 100 and moving it out oflocation or breaking off a piece of the stent 100. As can beappreciated, the occurrence of such events is difficult to detect butgenerally requires emergency surgery if detected in time, and thereforeis undesirable. It should be noted that in an embodiment the size of theside aperture 105 may be substantially the same as the openings in thestent 100 at the proximal and distal ends 101, 102 so as to providesubstantially the same effective lumen for each branch.

Referring to FIG. 22, a first marker 112, partially provided in dottedline, extends around a portion of the circumference of the stent 100. Ascan be appreciated, this configuration, while not required, is helpfulin positioning the stent. As can be further appreciated, the stentincludes a second marker 110 that has a first half on one side of top ofthe stent and a second half on the bottom of the stent 100. This allowsthe second marker 110 to effectively extend the length of the stent 100while providing additional information to the operator duringimplantation of the stent. For example, if the viewing angle is properlyaligned, the second marker 110 will appear to be a continuous line. Ofcourse, in an alternative embodiment the second marker 110 may be acontinuous line.

In an embodiment, the second marker 110 may be aligned with thelongitudinal axis of the stent 100. In an alternative embodiment, thesecond marker 110 may be aligned parallel to the longitudinal axis ofthe stent 100. As can be appreciated, a parallel configuration mayprovide more precise feedback to the operator during implantation butrequires additional manufacturing precision.

It should be noted that the first marker 112 may be positioned so as tobe perpendicular to the second marker 110. While such a position is notrequired, if the second marker 110 is parallel to the longitudinal axisand the first marker 112 is perpendicular to the second marker 110, theposition of the stent 100 can be more accurately determined prior toexpansion of the stent 100.

In this regard, it should be noted that when the stent 100 is in thenon-expanded state it is difficult to discern the location of the sideaperture 105. Thus, the use of one or more markers that are visiblewhile the stent 100 is still in the compressed state will tend toprevent the stent 100 from being expanded in an incorrect position. Forexample, as depicted in FIG. 24, a non-expanded stent 100 is shown intwo views and at least one of the first marker 112 and the second marker110 is/are visible on the compressed stent 100 in either view.

Returning to FIG. 12, a left coronary artery 40 is depicted with thestent 100 supporting the wall 43 from the main branch 42 to the firstbranch 44. However, to avoid blocking the second branch 46, the sideaperture 105 is aligned so as to allow blood to flow through the stent100 into the second branch 46. As can be appreciated, when installed thewall 43 will be in contact with most of the stent 100; thus, the stent100 will act as a support structure to help ensure that blood flow tothe branches 44, 46 remains non-obstructed.

While in many situations it may be sufficient to implant the stent 100,in other circumstances, such as depicted in FIG. 6a , it may bebeneficial to provide additional support for the wall 43. One way ofdoing so is to install a second stent. For example, a second stentextending from the side aperture 105 would provide a “Y” shaped supportstructure (FIG. 16) that could help ensure the blood continues to flowfrom the main branch 42 to the branches 44, 46.

To provide the “Y” shaped structure, first, as depicted in FIG. 13, aguide wire 72 is inserted into the left coronary artery 40 and guidedthrough the side aperture 105. This may be a different guide wire thanthe guide wire 70 or it may be the same guide wire. One potential issuewith inserting a guide wire into the left coronary artery 40 after thestent 100 is implanted is that the guide wire 72 has a limited abilityto bend and go around tight curves and could possibly catch on the stent100. As previously discussed, in an embodiment the side aperture 105 maybe elongated on one side. While not required, the elongated sideaperture allows the guide wire 72 to be inserted into the second branch46 while reducing the possibility that the guide wire might catch on thestent 100. In an alternative embodiment the side aperture 105 couldsimply be made larger.

Once the guide wire 72 is inserted, a catheter 82 is inserted along theguide wire 72 until the balloon 92 is positioned as desired. In anembodiment, as depicted in FIG. 14, the balloon 92 extends out of theside aperture 105 and includes a stent 115 mounted to the outside of theballoon 92. In an embodiment the side aperture is elongated so that theballoon 92 and stent 115 pass through the side aperture 105 withoutcatching on the stent 100. In an embodiment, when the stent 115 isexpanded the stent 115 and stent 100 will have some overlap. In analternative embodiment, the stent 115 will not overlap with the stent100 but will be positioned via the side aperture 105. In anotheralternative embodiment, the stent 115 may be positioned first and thenthe stent 100 may be positioned so that the side aperture 105 alignswith the stent 115. To provide maximum support, however, it may bebeneficial to have some overlap between the stent 100 and the stent 115.

In an alternative embodiment, as depicted in FIG. 15, a guide wire 74will be inserted past the proximal end 101 of the stent 100 and acatheter 84 with a balloon 94 will be inserted so that a portion of astent 116 overlaps with the stent 100. The balloon 94 may then beinflated so that the stent 116 and stent 100 provide a more complexsupport structure. It should be noted that it may be useful to use aballoon 94 with a lesser degree of compliance so that the stent 116 isexpanded in a uniform manner.

As illustrated in FIGS. 16 and 17, the stents 115, 116 are positionedand expanded to form a “Y” shaped support structure or an expandedtubular shaped support structure, respectively. In an embodiment, boththe stent 115 and the stent 116 may be added to the stent 100 tomaximize support of the left coronary artery 40. As can be appreciated,combinations of one or more stents 100, 115 and 116 may be used in anoverlapping fashion; thus, a complex support structure is possible. Itis expected, however, that one or two stents will typically besufficient.

It should be noted that in an alternative embodiment the stent 115 maybe a self-expanding stent. In such an embodiment, the stent 115 would bepositioned and then allowed to expand. In an embodiment theself-expanding stent 115 would include one or more markers to allow theoperator to more accurately determine where the proximal and/or distalends are located.

As can be appreciated, the size of stent 100 may be adjusted as desiredand used in other junction locations in different blood vessels. Forexample, the distance between the distal end 102 and the side aperture105 may vary as desired. In addition, different locations may require anouter diameter 103 of the stent 100 (FIG. 10) to be adjusted so as toprovide proper support for the wall of the blood vessel.

It should be noted that in an embodiment a stent 100 may be insertedafter the balloon is expanded a first time. In such an embodiment, afirst balloon would be expanded and then contracted. The first balloonwould then be removed. Next the stent 100 would be installed. In such ascenario the stent 100 could be a self-expanding stent or a balloonexpanded stent as discussed above. Thus, expanding a stent includesusing a balloon to expand the stent or allowing the stent toself-expand. As the general procedure for inserting and expanding astent in an artery is known to persons of skill in the art, additionaldetails are not provided herein.

As can be appreciated, care must be used when positioning the stent 100and the side aperture 105 and the optional stents 115, 116 or thesupport structure will not work as intended. For example, it isbeneficial to align the side aperture 105 with the second branch 46 soas to avoid occlusion of the second branch 46.

In an embodiment, the stent may be made of a stainless steel alloy,although other materials may be used. It is noted that the type of stentis not crucial; thus, for example but without limitation, a coiledspring design, a slotted tube design or mesh design may be used.However, one potential issue with the insertion of stents is that undercertain known viewing methodologies the stent will not be visible (e.g.the stent will be radiolucent). Even if the stent is not radiolucent,seeing the stent without being able to determine its orientation canmake aligning the side aperture more difficult.

To allow for improved orientation of the stent, radio-opaque markers maybe included on the stent. In an embodiment the markers may include agold coating; however, other coatings may also be used. Looking at FIG.18, a stent 100 includes a first marker 112, a second marker 110, athird marker 113 and a fourth marker 114. In an embodiment, as depicted,the first marker 112 and the second marker 110 may be perpendicular inorientation. The third and fourth markers 113, 114 may be positioned onproximal end 101 and distal end 102 of the stent 100. In an embodiment,a stent may have one or more of the markers as is appropriate. As can beappreciated, other shapes of markers other than lines may also be used.

It should also be noted the first marker 112 may include severaldistinct symbols that together form the first marker 112. Thus, the termmarker refers to a set of one or more symbols, and may be, for exampleand without limitation, a set of dots, a geometric shape or some otherconfigurations that allows the operator to determine aspects of theorientation of the stent 100. An advantage of using a line, however, isthe ease of viewing such a marker during implantation of the stent.

In an embodiment, the first marker 112 may extend around a radialportion of the stent 100 as depicted in FIG. 18. In an embodiment, thefirst marker 112 may extend around about half of the stent 100. Whilenot required, the advantage of having the first marker 112 extend aroundabout half of the stent 100 can be appreciated in light of FIGS. 19 and20. If the orientation of the stent is aligned with the angle ofviewing, the first marker 112 will look like a straight line, asillustrated in FIG. 19. If the orientation of the stent 100 is notaligned with the viewing angle, the first marker 112 will resemble theappearance of the first marker 112 in FIG. 20. As can be appreciated,this allows the operator positioning the stent 100 in the blood vesselto determine and/or verify the angular orientation of the stent 100.

In addition to allowing the determination of angular orientation,configuring the stent 100 to include the first marker 112 with the firstmarker 112 being “C” shaped can also allow the operator to determinewhether the rotational orientation of the stent is correct asillustrated by FIG. 21. Thus, the angular and rotational orientation maybe determined with the first marker 112 so that the stent 100 isproperly positioned before being expanded.

In an embodiment, the first marker 112 may be directly aligned with thecenterline 106 (FIG. 23) of the side aperture 105. Thus, the operatorpositioning the stent 100 can line up the first marker 112 with themiddle of the second branch 46 (FIG. 3) so as to maximize blood flow tothe second branch 46. As can be appreciated, however, the first marker112 may also be aligned with some other part of the side aperture 105.

In an embodiment, the first marker 112 may extend the length of thestent 100. While not required, such a configuration aids in theimplantation of additional stents. For example, in an embodiment asupport structure as depicted in FIG. 16 may be desired. To provide thedepicted support, first the stent 100 with the side aperture 105 may beinstalled. The first and second markers 110, 112 allow the stent 100 tobe properly orientated with respect to the second branch 46 before thestent 100 is expanded (FIGS. 8 and 9). In an embodiment the stent 115may include the third and fourth markers 113, 114, which may be alignedwith the proximal and distal ends of the stent 115, thus allowing thestent 115 to be aligned with respect to first and second markers 110,112. Therefore, a stent 115 with the third and fourth markers 113, 114may be positioned so as to partially extend from the side aperture 105(FIG. 14).

If the support structure as depicted in FIG. 17 is desired, in anembodiment where the first marker 112 extended the length of the stent100, the fourth marker 114 on the stent 115 could be positioned withrespect to the first marker 112 on the stent 100. Thus, in an embodimentit could be determined when there was an overlap because the two markers110, 114 would cross in a two-dimensional view. It should be noted thatthe same stent 115 may be used in either configurations shown in FIGS.16 and 17. In an alternative embodiment, however, a different stent maybe used. The advantage of using the same stent to obtain either thestructure in FIG. 16 or FIG. 17 is a reduced number of parts, thusreducing the chance that the wrong stent will be used. However, having avariety of different sized stents may allow for a more precise fit ifsuch a fit is found to be useful for a particular patient. For example,the secondary branch might be much smaller than the main branch and thuswould benefit from a stent with a smaller outer diameter.

FIGS. 25A and 25B show an exemplary stent 100 according to oneembodiment of the invention. Specifically, FIG. 25A shows a perspectiveside view of stent 100 and FIG. 25B shows a top view of exemplary stent100. As shown in FIGS. 25A and 25B, exemplary stent 100 includes aproximal end 101 and a distal end 102. A cylinder wall 104 that opens atthe proximal end 101 and the distal end 102 includes a side aperture105. Exemplary aperture 105 is shown to be substantially circular,however, those skilled in the art will realize that, similar to otherembodiments described herein, the aperture 105 is not required to becircular, but may assume any other shape, simple or complex, having aperimeter. In certain embodiments, the cylinder wall 104 of the stent100 is configured to allow the stent 100 to expand. The cylinder wall104 may comprise any of the known wall designs used for expandingstents.

As shown in FIG. 25B, the side aperture 105 is shown with a center line106. It is noted that in practice the center line 106 would not bevisible and is thus being provided as a reference for purpose ofdiscussion. In certain embodiments, the side aperture 105 may beelongated on one side of the center line 106, thus making it moredifficult to define the true center. For purpose of discussion, however,the center line 106 as used herein refers to an imaginary reference lineon the side aperture 105 that the operator should attempt to alignsubstantially with the center of a second branch 46 (FIG. 3).

Side aperture 105 is defined by perimeter 120. It should be noted thatas depicted, aperture 105 provides a relatively smooth edge in thecylinder wall 104. While not required, this may assist, in someembodiments, the insertion of a second stent through the side aperture105 with less likelihood of snagging the stent 100 and moving it out oflocation or breaking off a piece of the stent 100. As can beappreciated, the occurrence of such events is difficult to detect butgenerally requires emergency surgery, and therefore is undesirable. Itshould be noted that in an embodiment, the size of the side aperture 105may be substantially the same as the openings in the stent 100 at theproximal and distal ends 101, 102 so as to provide substantially thesame effective lumen for each branch.

Further aspects of the invention relate to stents having an extensionand methods for using novel stents with an extension. As shown in bothFIGS. 25A and 25B, stent 100 comprises an extension 122 that extendsfrom a portion of the perimeter 120 of the aperture 105. Extension 122may comprise one or more biocompatible substances and/or pharmaceuticalagents. In one embodiment, extension 122 is substantially the samecomposition as stent 100. As shown best in FIG. 25B, extension 122extends from the perimeter 120 in a substantially continuous form. Forexample, exemplary extension 122 extends around perimeter 120 betweenpoints 124 and 126. As used herein, “substantially continuous” meanswithout any substantial breakage. For example, extension 122 may haveperforations and/or areas of decreased thickness to assist in expansionand/or flexing of the extension 122, however, any such areas areconfigured to minimize or prevent any flow of fluids through those areasrather than through the pathway created by the aperture 105.

As shown in FIG. 25B, points 124 and 126 are located at about a midlineof the perimeter, thus in the illustrated embodiment, extension 122extends around approximately 50% of the perimeter. In yet otherembodiments, extension 122 may extend less than about 50%. In certainembodiments, the extension 122 extends approximately 30-40% of theperimeter 120. In certain embodiments, the extension may extend at leastabout 25% of the perimeter 120. In certain embodiments, the extension122 extends approximately 20-75% of the perimeter 120. In otherembodiments, extension 122 may extend more than about 95% of theperimeter. For example, on one side, extension 122 may extend a firstdistance away from the stent's cylinder wall 104, while on a secondside, extension 122 may extend a second distance away from the stentscylinder wall 104, in which the first distance is visually shorter thanthe second distance, when viewed during the implantation procedure usingconventional imaging equipment. Further, as shown in FIGS. 25A and 25B,the extension 122 may be shaped as to have a longitudinal axis that isneither directly parallel nor perpendicular with the longitudinal axisof the cylinder wall.

In certain embodiments, extension 122 is configured to extend outwardfrom the cylinder wall 104 and form a hood-like protrusion that archesover the perimeter 122. As used herein, “hood-like” refers to anextension that, if viewed from directly over and aligned with the centerof the perimeter 120 (i.e., perpendicular to the center of midline 106shown in FIG. 25B), the extension 122 would appear to cover at least aportion of the area within perimeter 120. In one embodiment, theextension may extend cover about 10% of area within perimeter 120. Incertain embodiments, the extension may extend at least about 25% of areawithin perimeter 120. In certain embodiments, the extension 122 maycover approximately 30-40% of the area within perimeter 120. In certainembodiments, the extension 122 may cover approximately 20-75% of thearea within perimeter 120.

Those skilled in the art will appreciate that the extent to which theextension 122 extends over (and thus cover the area within) perimeter120 depends on one or more factors, including for example, the intendedimplantation site of stent 100. Furthermore, in certain embodiments, thestent is configured to be flexible, such that without pressure from, forexample, being implanted in a branch, it is designed to flex to acertain position, however, upon being implanted, may flex to a secondposition. Thus, in one embodiment, extension 122 may be configured tocover about 10% of the area within perimeter 120, however, uponimplantation, flexes to cover more than 10% of the area within perimeter120.

In the exemplary embodiment shown in FIGS. 25A and 25B, edge 128 ofextension 122 arches over the perimeter in a latitudinal direction thatis perpendicular to the longitudinal axis of the cylinder wall 104.Specifically, edge 128 of extension 122 is shown to extend in asubstantially latitudinal direction at the location where the distanceof the aperture along the latitudinal direction is the greatest. (e.g.,midline 106, shown in FIG. 25B). Those skilled in the art will readilyappreciate, however, that the arch is not required to be located in asubstantially latitudinal direction. In certain embodiments, edge 128may arch is a substantially longitudinal direction (e.g. if extension122 was rotated about 90 degrees to the right or to the left). In otherembodiments, extension 122 may be off-axis with respect to thelatitudinal and longitudinal directions as shown in FIGS. 25 and 25B.Moreover, as discussed above, edge 128 is not required to extend overthe perimeter 122 at about midline 106.

FIG. 26A shows a perspective side view of stent 100 and FIG. 26B shows atop view of exemplary stent 100. Similar to the embodiment displayed inFIGS. 25A and 25B, the embodiments shown in FIGS. 26A and 26B depict anextension 122 that is configured to extend outward from the cylinderwall 104 and form a hood-like protrusion that arches over the perimeter120. Edge 128 of FIGS. 26A and 26B, however, are not straight, ratheredge 128 initiates at about points 124 and 126 and extends in a wavelike fashion, first extending away from the midline 106 and subsequentlyback towards the midline 106 as the hood-like extension 122. Forexample, in the illustrated embodiment, point 130 represents thefurthest distance the exemplary extension 122 extends away from theperimeter 120 of the aperture 105 (i.e., similar to an apex of an arch).Thus, as shown in FIGS. 26A and 26B, edge 128 (and/or any resultingarching structure) is not required to be straight.

While the exemplary embodiment of FIGS. 26A and 26B shows point 130 asbeing substantially directly over midline 106, those skilled in the artwill appreciate that this is just one embodiment, and point 130, whileover a portion of the perimeter 120, is not required to be positioned atabout a midline 130. Moreover, those skilled in the art will alsoappreciate that there are several other shapes and/or configurations forthe arching behavior of edge 128, including but not limited to:adjusting flexibility/rigidity, tools and/processes used to implant thestent 100, specific conditions of the patient the stent may be implantedwithin, and others. (Exemplary methods for implantation were discussedabove and additional methods are discussed below).

In one embodiment, extension 122 may be flexible to expand from a firstposition to a second position. FIG. 27 shows a perspective side view ofan exemplary stent 100 according to one embodiment of the invention.Looking to FIG. 27, stent 100 comprises an extension 122 in a firstposition. As seen, extension 122 is substantially within perimeter 120of aperture 105. As used herein, substantially within means thatextension 122 does not extend out of aperture 105 in a manner that wouldaversely affect insertion and/or implantation of the stent 100 into apatient. Extension 122 may expand to a second state upon an event orunder predefined criteria. In certain embodiments, extension 122 may beconfigured to flex outward from the cylinder wall 104 upon expansion ofthe stent 100. For example, upon being expanded to the second state, theextension 122 may form a form a hood-like protrusion that over theperimeter 120 (e.g. as shown in FIGS. 25A, 25B, 26A and/or 26B).

In one embodiment, a partially-compliant balloon may be utilized toexpand cylinder wall 104 and extension 122. In one embodiment, apartially-complaint balloon is positioned within a stent with acompliant portion of the balloon being positioned about the extension122. Upon expanding the balloon, a non-compliant portion of the balloonmay expand the cylinder body 104, however, a compliant portion of theballoon may expand further than the non-compliant portion of the balloonand, therefore, expand extension 122 from the first state to the secondstate. In other embodiments, expansion of the stent 100, alone, may notautomatically trigger expansion of the extension 122 to a second state.Other events that may trigger the expansion of the extension 122 fromthe first state the second state, include but may not be limited to:using the same or another balloon to expand extension 122 to the secondstate after the cylinder body 104 has been expanded.

FIG. 28 shows an exemplary stent 100 upon being implanted in a patient.In one embodiment, extension 122 has been extended from a first state(e.g. as shown in FIG. 27) and is shown in the second state. FIG. 28shows implantation of the stent 100 in the left coronary artery;however, those skilled in the art will appreciate that stents inaccordance with one or more embodiments disclosed herein may be used inone or more other vessels within a body (human or non-human). As shown,the left coronary artery 40 is shown in an enlarged view that includesthe left main artery or main branch 42 that feeds a first branch 44(which as depicted is the left anterior descending artery) and a secondbranch 46 (which as depicted is the left circumflex artery). As can befurther appreciated, the main branch 42 includes a wall 43. In order forblood to flow through the left coronary artery 40, the wall 43 forms atube-like shape that preferably is free from blockage.

In one embodiment, a method may be employed that positions stent 100 tohave aperture 105 in the junction of the first branch 43 and the secondbranch 44. As seen, aperture 105 extends along a longitudinal directionand along a latitudinal direction to form a perimeter 120. In oneembodiment, stent 100 may include marker 132 which may be aligned withthe side aperture 105 at a location the first marker is in-line with anddirectly extends from the location where the distance of the aperturealong the latitudinal direction is the greatest, the first markerextending along a circumference of the stent a distance substantiallyperpendicular to a longitudinal axis of the stent so as to provide arotational orientation of the stent in a two dimensional image.

Those skilled in the art will readily appreciate that marker 132, and/orother markers, may not be apparent or properly viewed in a collapsedstent, such as before the stent 100 is expanded in those embodimentswhere stent 100 is expandable from a first state to a second state. Inthis regard, embodiments of the invention relate to an expanding stent(i.e, so as to support the wall of the main branch and the firstbranch), whereby the side aperture allows the main branch 43 to continueto feed both the first branch 44 and the second branch 46. In furtherembodiments, the extension 122 may be flexible as to be expandable froma first state (e.g., as shown in FIG. 27) to a second state (e.g., shownin FIGS. 25-26 and/or 28). In one embodiment, extension 122 may beextended to be in a substantially continuous form from a portion of theside aperture's 105 perimeter 120 that flexes outward from the cylinderwall 104 to form a protrusion that arches in a direction over theperimeter 120 and extending into the second branch 46. As shown,extension 122 extends in a direction that is substantially aligned withthe longitudinal axis (shown as dotted lines 134) of the second branch46. In the exemplary embodiment, edge 128 of extension 122 issubstantially parallel to the longitudinal axis 134 of the second branch46. As discussed above, however, there is no requirement that edge 128be directly parallel to any axis, but rather may include one or morecurving structures.

In one embodiment, the extension 122 expands as a result of theexpansion of the stent 100. As discussed above, one or more otherevents, actions, and/or predefined criteria may have to be met for theexpansion of an extension from a first state to a second state. In oneembodiment, the expansion of the extension 122 may occur after theexpansion of the stent 100.

Use of the novel stent 100 may overcome one or more shortcoming in theart. As one example, various procedures require the implantation ofmultiple stents in a single location. Often two or more stents arejoined together. Looking to FIGS. 29A and 29B, stent 290 is generally inthe shape of a cylindrical body. Stent 291 is connected to stent 290. Asseen in FIG. 29A, stent 291 is connected to stent 290 at an angle, andthus, a portion of stent 292 (which is represented by the dotted lines)is within stent 290. For example, point 292 is located at about thejunction where stents 290 and 291 meet. At point 292 any insertion ofstent 291 within 290 is minimal, however, looking to point 293, it iswithin stent 290, and as such may slow the passage of any fluids withinstent 290. Those skilled in the art will readily appreciate thatblocking bodily fluids, whether blood or waste products, can lead todangerous and lethal consequences.

Conversely, FIG. 29B shows an embodiment where stent 291 is notsubstantially within stent 290. For example, point 203 is located atabout the junction where stents 290 and 290 meet. In this instance,however, point 292 is no longer at the junction. Rather gap 294 iscreated between the stents 290, 291. This may result in undesired growthor collection of matter between the two stents. Further, it may lead toinadequate support at the juncture. In accordance with certain aspectsof the invention, implementing extension 122 on either stent 290 and/orstent 291, may minimize or negate the problems associated with thearrangement of FIGS. 29A and FIGS. 29B. In this regard, certainembodiments of extension 122 may be configured to receive a secondstent. Alternatively, in other embodiments, extension 122 may beconfigured to be received a by a second stent.

Further aspects relate to one or more markers being located on theextension 122. FIGS. 30-31 show exemplary stents having one or moremarkers on an extension in accordance with various embodiments. Lookingfirst to FIGS. 30A and 30B, stent 100 comprises extension 122. As shown,marker 138 on the extension 122 arches substantially in a latitudinaldirection over the perimeter in a direction that is substantiallyperpendicular to a longitudinal axis of the cylinder wall 104 of thestent 100. As shown, marker 138 is approximately located on edge 128. Inone embodiment, marker 138 extends a distance to permit the capture of arotation orientation of the extension in a dimensional image. In certainembodiments, marker 138 may not be entirely or even partiallyperpendicular to the longitudinal axis of the cylinder wall 104. Forexample, in embodiments, for example as shown in FIGS. 26A and 26B, edge128 may not be straight, and as such in such embodiments in which marker138 marks the edge 128, the marker 138 may not follow a straight path.

As appreciated by those skilled in the art, if extension 122 was rotatedapproximately 90 degrees to the right or to the left, marker 138 wouldbe substantially parallel with (and in some embodiments, directly inline with) the longitudinal axis of the cylinder wall 104 of stent 100.Thus, in this illustrated embodiment and in others, marker 138 may be inline with either the longitudinal axis or the latitudinal axis of thecylinder wall 104. In this regard, marker 138 may have more than twocomponents, and thus be parallel with (and possibly also inline with)the longitudinal and/or the latitudinal axis of the cylinder wall 104.Looking to FIGS. 31A and 31B, for example, marker 140 is substantiallyparallel with the longitudinal axis of cylinder wall 104. In thisillustrated embodiment, marker 140 is also directly inline with thelongitudinal axis of the cylinder wall 104 (best seen in FIG. 31B). Inone embodiment, marker 138 and/or marker 140 may be positioned totraverse the location at which the extension 122 is furthest away fromthe aperture 105. In one embodiment, marker 138 may comprise an archacross the furthest point away from the side aperture 105.

In certain embodiments, one or more markers are configured so as toappear substantially perpendicular to each other in a two dimensionalimage. In certain embodiments, extension 122 may comprise a marker andthe cylinder wall 104 of the stent 101 may comprise a marker. Lookingagain to FIGS. 30A and 30B, cylinder wall 104 may also comprise one ormore markers. Marker 142, for example, is positioned adjacent the sideaperture 105. In certain embodiments, marker 142 may extend a distanceat least equal to a greatest longitudinal distance (as referenced fromthe cylinder wall 104) of the side aperture 105. In other embodiments,marker 142 may be shorter than the distance of the aperture, however,marks the location where the extension 122 meets the cylinder body 104,point 130 (shown in FIGS. 26A and 26B) and/or any other location on theextension 122.

Looking again to FIGS. 31A and 31B, stent 101 may comprise a marker(such as marker 144) that is positioned in-line with and directlyextending from the location where the distance of the aperture 105 alongthe latitudinal direction (as referenced from the cylinder wall 104) isthe greatest. In one embodiment, marker 144 may extend a portion of adistance around the circumference of the cylinder wall 104 in adirection extending away from the side aperture 105 and substantiallyperpendicular to a longitudinal axis of the cylinder wall 104 so as toprovide a rotation orientation of the stent in a two-dimensional image.In one embodiment, marker 144 is directly aligned with a centerline ofthe side aperture 105. In one embodiment, marker 144 may extend entirelyaround the cylinder wall 104 and terminate at about the other side ofthe aperture 105. In one embodiment, marker 140 may creates an archacross the furthest point away from the aperture 105.

The present invention has been described in terms of preferred andexemplary embodiments thereof. Numerous other embodiments, modificationsand variations within the scope and spirit of the appended claims willoccur to persons of ordinary skill in the art from a review of thisdisclosure.

We claim:
 1. A stent system configured to support a wall of at least onejunction of a bodily vessel, the junction comprising a main branch, afirst branch and a second branch, comprising: a stent having a cylinderwall configured to be expanded from a first state to a second state,wherein at the first state, the cylinder wall comprises a firstcircumference along a length extending from a first end to a second endalong a first axis, a side aperture located at a fixed position withrespect to the first and the second ends having a perimeter, and aflexible extension positioned substantially within the circumference;and wherein at the second state, the cylinder wall is configured toexpand along its length configured to support the wall of the mainbranch and the first branch, to form a second circumference, wherein thesecond circumference is variable along the length of the cylinder andthe flexible extension is configured to extend from a predefined portionof the side aperture's perimeter that, upon expansion of the stent, isconfigured to flex outward from the cylinder wall to form a hood-likeprotrusion that arches over the perimeter; and a first marker that uponexpansion of the stent, is positioned in-line with and directlyextending from a location where the distance of the aperture along thelatitudinal direction is the greatest.
 2. The stent system of claim 1,wherein the marker extends a portion of a distance around thecircumference of the cylinder wall in a direction extending away fromthe side aperture and substantially perpendicular to a longitudinal axisof the stent so as to provide a rotation orientation of the stent in atwo-dimensional image.
 3. The stent system of claim 1, furthercomprising a second marker positioned on the flexible extension, whereinthe second marker arches in a latitudinal direction over the perimeterin a direction that is substantially perpendicular to a longitudinalaxis of the stent so as to provide a rotation orientation of theextension in a two-dimensional image.
 4. The stent system of claim 1,wherein the stent is a first stent, the system further comprising asecond stent configured to be at least partially positioned through theside aperture of the first stent.
 5. The stent system of claim 4,wherein the second stent is configured to be expanded upon beingpartially positioned through the first stent, whereby the first andsecond stent form a support structure.
 6. The stent system of claim 1,wherein the side aperture is a first side aperture, the stent comprisinga second side aperture.
 7. The stent system of claim 6, wherein thefirst side aperture and the second side apearture comprise a samediameter.
 8. The stent system of claim 1, further comprising a secondmarker positioned on the flexible extension that forms an arch acrossthe furthest point away from the aperture.
 9. The stent system of claim1, wherein cylinder wall includes a wall structure, the wall structureselected from the group consisting of a mesh design, a coil springdesign and a slotted tube design.
 10. The stent system of claim 1,wherein the stent is a mesh-type stent and the stent is coated with ananti-neointimal proliferation agent.
 11. A stent system configured tosupport a wall of at least one junction of a bodily vessel, the junctioncomprising a main branch, a first branch and a second branch,comprising: a first stent having a cylinder wall configured to beexpanded from a first state to a second state, wherein at the firststate, the cylinder wall comprises a first circumference along a lengthextending from a first end to a second end along a first axis, a firstside aperture located at a fixed position with respect to the first andthe second ends having a first perimeter, and a flexible extensionpositioned substantially within the circumference; a second stent havinga cylinder wall configured to be expanded from a first state to a secondstate; wherein at the second state, the cylinder wall of the first stentis configured to expand along its length configured to support the wallof the main branch and the first branch, to form a second circumference,wherein the second circumference and the flexible extension isconfigured to extend from a predefined portion of the side aperture'sperimeter that, upon expansion of the stent, is configured to flexoutward from the cylinder wall to form a hood-like protrusion thatarches over the perimeter; and a first marker that upon expansion of thefirst stent, is positioned in-line with and directly extending from alocation where the distance of the aperture along the latitudinaldirection is the greatest.
 12. The stent system of claim 11, whereinwhen the first stent is at the second state, its circumference isvariable along the length of its cylinder wall.
 13. The stent system ofclaim 11, wherein the second stent is configured to be at leastpartially positioned through the side aperture of the first stent whenthe second stent is at the first state.
 14. The stent system of claim13, wherein the second stent is configured to be expanded to the secondstate upon being partially positioned through the first stent, wherebythe first and second stent form a support structure.
 15. The stentsystem of claim 11, wherein the marker extends a portion of a distancearound the circumference of the cylinder wall in a direction extendingaway from the side aperture and substantially perpendicular to alongitudinal axis of the stent so as to provide a rotation orientationof the stent in a two-dimensional image.
 16. The stent system of claim11, further comprising a second marker positioned on the flexibleextension, wherein the second marker arches in a latitudinal directionover the perimeter in a direction that is substantially perpendicular toa longitudinal axis of the stent so as to provide a rotation orientationof the extension in a two-dimensional image.
 17. The stent system ofclaim 11, wherein at the second state, the cylinder wall of the firststent is variable along the length of the cylinder wall.
 18. The stentsystem of claim 11, wherein the first stent comprises a second sideaperture.
 19. The stent of claim 18, wherein the first side aperture andthe second side aperture comprise a same diameter.
 20. The stent ofclaim 1, further comprising a second marker positioned on the flexibleextension that forms an arch across the furthest point away from theaperture of the first stent.